In an image forming apparatus such as a multi-function peripheral (MFP), to press toner on a sheet or a document for printing, a fixing device including a single heater element or a plurality of heater elements is used. Since an MFP including a plurality of heater elements causes only the heater elements corresponding to the actual printing area on the sheet to generate heat, power consumption can be reduced relative to an MFP with a single heater element.
Some MFPs having a plurality of heater elements cause only a predetermined number of heater elements located on a transportation path of a sheet to generate heat. In such MFPs, printing may not be performed accurately when the sheet is not transported along the correct path due to an error in assembling components, an incorrect placement of the sheet by a user, degradation of the components over time, or an issue caused when the product is shipped.